1. Field of the Invention
The present invention relates to an adhesive material applying method and apparatus, interconnect substrate, semiconductor device and method of its production, circuit board and electronic instrument.
2. Description of Related Art
Recently, there is being used an anisotropic conductive film (ACF) when semiconductor chips are to be electrically connected to an interconnect pattern on a package substrate in a process of assembling a semiconductor device to which ball grid array (BGA) or chip scale/size package (CSP) is applied.
Such an anisotropic conductive film is formed by forming an adhesive containing dispersed conductive particles such as Ni, Au, Cu on a base film. The semiconductor chip is adhered to the package substrate through the conductive particles so that the semiconductor chips will electrically be connected to the interconnect pattern.
The anisotropic conductive film applied according to the prior art process may contain air bubbles at the corners between the interconnect pattern and the package substrate. Air bubbles may burst in the subsequent step such as a temporary pressurizing step (for about ten seconds at a relatively low temperature of about 100xc2x0 C.) or a main pressurizing step (for about 15 seconds at about 220xc2x0 C.). This raises a problem in that the anisotropic conductive film is separated from the package substrate.
To overcome such a problem, an objective of the present invention is to provide an adhesive material applying method and apparatus, interconnect substrate, semiconductor device and manufacturing method thereof, circuit board and electronic instrument which can remove air bubbles.
(1) According to a first aspect of the present invention, there is provided a method of applying an adhesive material, comprising the steps of: providing an adhesive material on an interconnect substrate which has a base and an interconnect pattern formed on the base; and pressure-bonding the adhesive material onto the interconnect substrate,
wherein the base has a plurality of first regions to be punched out and second regions located between the first regions adjacent to one another;
wherein the interconnect pattern is formed at least in the first regions of the base; and
wherein part of the adhesive material provided in the first regions is pressurized to flow toward the second regions, so that air bubbles formed at corners between the base and the interconnect pattern in the first regions are moved to the second regions.
According to this aspect of the present invention, air bubbles are formed at the corners between the base and the interconnect pattern in the first regions when providing the adhesive material to the interconnect substrate since it is difficult to completely fill the corners with the adhesive material. However, part of the adhesive material including air bubbles in the first regions is moved to the second regions, when the adhesive material is pressure-bonded onto the interconnect substrate. Since the amount of air bubbles in the first regions can be reduced, products having such interconnect substrates can be provided with a reduced probability of failure. This improves the productivity and yield. The presence of air bubbles in the second regions will not raise any problem since the second regions have been left after the first regions have been punched out.
(2) In the method of applying an adhesive material, through-holes may be formed in the second regions of the base of the interconnect substrate; and the adhesive material may be pressurized to flow into the through-holes.
Thus, the air bubbles in the first regions are moved to the second regions when the adhesive material flows into the through-holes in the second regions.
(3) In the method of applying an adhesive material, the interconnect pattern may include leads formed in the second regions; and the through-holes may penetrate the leads and the base.
Thus, the air bubbles in the first regions are moved when the adhesive material flows through the through-holes formed in the leads in the second regions.
(4) In the method of applying an adhesive material, the interconnect pattern may include leads formed in the second regions; and the through-holes may be formed adjacent to the leads.
Since the through-holes are formed adjacent to the leads, the adhesive material and the air bubbles can be easily moved without being obstructed by the leads.
(5) In the method of applying an adhesive material, the interconnect substrate may include depressions formed within the second regions on a surface of the base opposite to another surface of the base on which the interconnect pattern is formed; and the surface having the interconnect pattern is dented toward the depressions so that the adhesive material flows when the adhesive material is pressurized.
In this way, the surface of the base on which the interconnect pattern is formed can be dented toward the other surface of the base on which the depressions are formed so that the adhesive material flows toward the dent and the air bubbles moves to the second regions.
(6) In the method of applying an adhesive material, the interconnect pattern may include leads formed in the second regions; and the depressions may be formed below the leads.
Thus, the base can be dented toward the depressions through the leads. Since the adhesive material can flow toward the dent, the air bubbles can also be moved to the second regions.
(7) In the method of applying an adhesive material, a pressurizing jig may be used to pressure-bond the adhesive material onto the interconnect substrate; the pressurizing jig may be formed with depressions at positions corresponding to the second regions of the base; and the adhesive material may be pressurized to flow toward the depressions.
Thus, the adhesive material will be moved, together with air bubbles, toward the depressions in the pressurizing jig.
(8) In the method of applying an adhesive material, the interconnect substrate may be placed on a stand so that the adhesive material is pressure-bonded to the interconnect pattern; the stand may have depressions at positions corresponding to the second regions of the base; and when the adhesive material is pressurized, the surface of the base on which the interconnect pattern is formed may be dented toward the depressions so that the adhesive material flows.
Thus, the adhesive material can be moved, together with the air bubbles, toward the depressions in the stand.
(9) In the method of applying an adhesive material, spaces may be formed in the adhesive material at positions above the second regions of the base so that the adhesive material flows into the spaces later.
Thus, the adhesive material in the first regions will be moved, together with the air bubbles, into the spaces above the second regions.
(10) In the method of applying an adhesive material, the interconnect pattern may include leads formed in the second regions; and the magnitude of each of the spaces may be larger than each of the leads.
Thus, the adhesive material and the air bubbles can easily move without being obstructed by the leads.
(11) In the method of applying an adhesive material, the first regions may be arranged in plural rows and columns.
(12) In the method of applying an adhesive material, the adhesive material may be provided in a form of a film to be pressure-bonded to the interconnect substrate.
(13) In the method of applying an adhesive material, the adhesive material may be provided in a form of a liquid to be pressure-bonded to the interconnect substrate.
(14) According to a second aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising the steps of:
applying the adhesive material to the interconnect substrate by the method of applying an adhesive material as defined in claim 1;
bonding semiconductor chips to the respective first regions through the adhesive material; and
punching out the interconnect substrate at each of the first regions.
According to this aspect of the present invention, since a semiconductor device to be produced includes only the first regions having reduced air bubbles, the products can be provided with a reduced probability of failure, improving the productivity and yield.
(15) According to a third aspect of the present invention, there is provided an interconnect substrate comprising:
a base;
an interconnect pattern formed on the base; and
a adhesive material bonded to the base and interconnect pattern,
wherein the base has a plurality of first regions to be punched out and second regions located between the first regions adjacent to one another;
wherein the interconnect pattern is formed at least in the first regions of the base; and
wherein air bubbles formed between the base and the interconnect pattern in the first regions are moved to the second regions.
According to this aspect of the present invention, since the amount of air bubbles is reduced in the first regions, the products having such interconnect substrates can be provided with a reduced probability of failure, improving the productivity and yield. On the other hand, the presence of air bubbles in the second regions will not raise any problem since the second regions have been left after the first regions have been punched out.
(16) In the interconnect substrate, through-holes may be formed in the second regions of the base; and part of the adhesive material may flow into the through-holes.
Flowing of part of the adhesive material into the through-holes in the second regions proves movement of the air bubbles from the first regions to the second regions.
(17) In the interconnect substrate, the interconnect pattern may include leads formed in the second regions; and the through-holes may penetrate the leads and the base.
Thus, part of the adhesive material can flow into the through-holes in the leads and the base.
(18) In the interconnect substrate, the interconnect pattern may include leads formed in the second regions; and the through-holes may be formed adjacent to the leads.
Thus, the adhesive material and the air bubbles can be easily moved without being obstructed by the leads.
(19) In the interconnect substrate, depressions may be formed within the second regions on a surface of the base opposite to another surface of the base on which the interconnect pattern is formed.
Due to the depressions, the surface of the base opposite to the surface thereof on which the depressions are formed can be easily dented so that the adhesive material can flow toward the dent. Therefore, presence of the depressions in the interconnect substrate proves movement of the air bubbles from the first regions to the second regions.
(20) In the interconnect substrate, the interconnect pattern may include leads formed in the second regions; and the depressions may be formed below the leads.
Thus, the surface of the base opposite to the surface thereof on which the depressions are formed can be dented through the leads.
(21) According to a fourth aspect of the present invention, there is provided an apparatus of applying an adhesive material which has a pressurizing jig and a stand for pressure-bonding the adhesive material to an interconnect substrate having a base and an interconnect pattern formed on the base,
wherein the base has a plurality of first regions to be punched out and second regions located between the first regions adjacent to one another;
wherein the interconnect pattern is formed at least in the first regions of the base;
wherein at least one of the pressurizing jig and the stand has depressions at positions corresponding to the second regions of the base; and
wherein part of the adhesive material provided in the first regions is pressurized to flow toward the second regions so that air bubbles formed at corners between the base and the interconnect pattern are moved toward the depressions.
Thus, the adhesive material can be moved, together with the air bubbles, toward the depressions in the pressurizing jig or the stand.
(22) According to a fifth aspect of the present invention, there is provided a semiconductor device manufactured by the aforementioned method.
(23) According to a sixth aspect of the present invention, there is provided a circuit board to which aforementioned semiconductor device is electrically connected.
(24) According to a seventh aspect of the present invention, there is provided an electronic instrument having the aforementioned semiconductor device.